Siloxanes may be produced from the hydrolysis of organohalosilanes, which are typically produced in the direct process where silicon metal is reacted with an organohalide in the presence of catalyst, such as copper chloride. Processes have been explored to influence the production of some siloxanes over others in the hydrolysis of organohalosilanes, but these methods have limitations. There have also been processes developed to produce siloxanes from other siloxanes by rearrangement or equilibration reactions.
One type of such equilibration reaction comprises reacting siloxanes in the presence of an equilibration catalyst such as an ion exchange resin catalyst. However, the reaction rates and ability to reuse ion exchange catalysts can be improved with these equilibration catalysts. The ion exchange catalyst is typically severely reduced after a single use in one equilibrium reaction such that new ion exchange resin catalyst must be used in subsequent equilibrium reactions. Thus, the reaction time and disposal of the ion exchange catalyst can add significant costs to equilibration processes for producing siloxanes.
The inventors have found that the time of reaction for equilibrium reactions including ion exchange resin catalysts may be reduced by adjusting the water content, within limits, of the ion exchange resin catalyst in the reaction. In some cases, the time of reaction can be reduced by as much as 50% compared to when equilibrium reactions are conducted with an ion exchange resin outside of the water content limits described herein. The inventors have also found that by readjusting the water content of an ion exchange catalyst to within limits after it has been used in an equilibrium reaction that the ion exchange resin catalyst may be reused in subsequent reactions.